He wrote over twenty works of a historical nature, but only the Kitab al-Maghazi has survived as an independent work. Waqidi's authorities include Musa b. `Uqba, and he made extensive use of Ibn Ishaq's work. He was a Shiite, and his zeal for `Ali is revealed in the details in his history. He is especially important for having established the chronology of the early years of Islam. He is frequently cited by al-Tabari, who also relied upon him for variant narratives. Both Ibn Ishaq and al-Waqidi's reputations have suffered in recent years as a consequence of the trenchant criticisms by Patricia Crone, especially in Meccan Trade and the Rise of Islam , pp. 203-30), where she argues that much of the classical Muslim understanding of the Koran rests on the work of storytellers and that this work is of very dubious historical value. These storytellers contributed to the tradition on the rise of Islam, and this is evident in the steady growth of information: "If one storyteller should happen to mention a raid, the next storyteller would know the date of this raid, while the third would know everything that an audience might wish to hear about it." Then, comparing the accounts of the raid of Kharrar by Ibn Ishaq and al-Waqidi, Crone shows that al-Waqidi, influenced by and in the manner of the storytellers, "will always give precise dates, locations, names, where Ibn Ishaq has none, accounts of what triggered the expedition, miscellaneous information to lend color to the event, as well as reasons why, as was usually the case, no fighting took place. No wonder that scholars are fond of al-Waqidi: where else does one find such wonderfully precise information about everything one wishes to know? But given that this information was all unknown to Ibn Ishaq, its value is doubtful in the extreme. And if spurious information accumulated at this rate in the two generations between Ibn Ishaq and al-Waqidi, it is hard to avoid the conclusion that even more must have accumulated in the three generations between the Prophet and Ibn Ishaq."